Clutch with a wear indicator

Abstract

Wear indication for a clutch comprehensive - a clutch actuation travel indicator (1) whose position depends on the length of a clutch actuation travel; - a sensor that is set up to determine the position of a position transmitter based on a measured quantity; - the position transmitter, which is in a measurable positional relationship to the sensor, in that the position transmitter and the sensor have a variable position relative to each other; - an ECU that is configured to assign a length of clutch actuation travel to a position of the position sensor and to determine a wear degree of the clutch from this.

Description

AREA OF INVENTION

[0001] The present invention relates to a wear indicator for a clutch and a clutch with a wear indicator. SUMMARY OF THE INVENTION

[0002] Accordingly, the following is planned: - a wear indicator for a clutch comprising a clutch actuation travel indicator whose position depends on the length of a clutch actuation travel; a sensor configured to determine the position of a position encoder based on a measured quantity; the position encoder, which is in a measurable positional relationship to the sensor, in that the position encoder and the sensor have a variable position relative to each other; an ECU configured to assign a length of clutch actuation travel to a position of the position encoder and to determine a degree of clutch wear from this.

[0003] An ECU is an electronic control unit that receives signals from one or more sensors, processes them, and sends corresponding control commands to actuators to control certain functions in the vehicle.

[0004] A sensor, also known as a detector, transducer, or probe, is a technical component that can qualitatively or quantitatively detect certain physical or chemical properties or conditions, such as temperature, humidity, pressure, speed, brightness, acceleration, pH value, ionic strength, electrochemical potential, and / or the material composition of its environment. These quantities are detected using physical or chemical effects and converted into a processable electrical signal as sensor data.

[0005] Vehicle sensors can be mounted on a vehicle or are already mounted on it.

[0006] A Hall sensor uses the Hall effect to measure magnetic fields and convert them into electrical signals. The Hall effect occurs when an electric current flows through a conductive material and a magnetic field is applied perpendicular to this current, resulting in a transverse voltage known as the Hall voltage. This voltage is proportional to the strength of the magnetic field.

[0007] A typical Hall sensor consists of a thin layer of conductive material through which a constant current flows. When a magnetic field is applied perpendicular to this layer, a Hall voltage is generated, which is measured by electrodes on the sides of the layer.

[0008] A servo cylinder in a clutch is a component used to reduce the force required to actuate the clutch and to make clutch operation easier. It is a cylinder that provides hydraulic or pneumatic assistance to amplify the manual force the driver applies to the clutch pedal. This results in smoother and more precise clutch operation. The servo housing is the outer casing of the servo cylinder.

[0009] In a clutch system that uses both a booster cylinder and a servo cylinder, these two components work together to optimally amplify the actuation force and make clutch operation easier for the driver. The booster cylinder is connected to the clutch fork and amplifies the force applied by the driver through hydraulic pressure from a master cylinder. When the driver depresses the clutch pedal, hydraulic fluid is forced into the booster cylinder. The piston in the booster cylinder moves due to this pressure, increasing the force transmitted to the clutch fork and ultimately to the clutch.

[0010] The servo cylinder, located behind the booster cylinder, further amplifies the actuation force. When pressurized fluid is introduced into the servo cylinder, the piston inside moves, generating additional force that further facilitates clutch operation.

[0011] The interplay of these two cylinders ensures that the force applied by the driver is amplified by both the hydraulic booster cylinder and the pneumatic servo cylinder. First, the driver generates hydraulic pressure by depressing the clutch pedal, which is directed to the booster cylinder. The booster cylinder amplifies this force and transmits it to the clutch fork. Simultaneously, compressed air is directed to the servo cylinder, generating additional amplification that further increases the overall actuation force. This interaction allows for smoother and lighter clutch operation.

[0012] The length of the clutch actuation travel is the distance traveled by a specific component of the clutch system to fully engage the clutch. This length can refer to the travel of the clutch pedal, piston rod, pushrod, or another relevant component. These travel distances are correlated and determine the overall function of the clutch actuation.

[0013] A clutch actuation travel indicator is one or more means by which the length of the clutch actuation travel can be read. A suitable clutch actuation travel indicator is a pushrod whose position depends on the length of the clutch actuation travel.

[0014] A positional relationship describes the relative position between a sensor and a position transmitter. If the position transmitter or the sensor is fixed, the absolute position of the moving component, for example the position transmitter, can also be determined from the positional relationship between these two components. This relationship makes it possible to determine the position of the position transmitter based on a measurable quantity using a sensor.

[0015] A piston rod is a rod-shaped component integrated into a servo cylinder that transmits the force and movement of the piston to the mechanical actuating element of a clutch.

[0016] A push rod is a rod-shaped component used to transmit mechanical forces or movements between different components.

[0017] A human-machine interface (HMI) allows an operator to control a machine, an electrical or electronic device, and optionally to monitor machine states and intervene in a controllable process. Information ("feedback") can be provided via control panels with indicator lights, displays, or buttons, or via software through a visualization system running, for example, on a terminal. A light switch is an example of an HMI. The driver's area of ​​a vehicle also features numerous HMIs – from the control devices (pedals, steering wheel, gearshift and turn signal levers, etc.) to the visual feedback from the vehicle itself (displays for speed, range, radio program, navigation system, etc.).

[0018] An actuating device is a human-machine interface. Suitable actuating devices for operating a clutch include, for example, pedals or control levers near a steering wheel.

[0019] This application addresses the problem of wear monitoring in couplings. In particular, the application offers improvements regarding the monitoring of the wear level of a coupling. Conventional couplings do not provide a way to monitor the wear condition of the coupling during operation. This can lead to unexpected failures and costly repairs.

[0020] Wear and tear occurs in mechanical components such as a clutch when they are subjected to prolonged stress. This leads to material fatigue and abrasion due to friction, heat, and mechanical loads. In a clutch, this can cause friction discs to become thinner, springs to lose tension, or bearings to wear out.

[0021] When the clutch disc wears down, material is worn away, causing it to erode. This increases the clutch engagement travel.

[0022] A digital wear indicator is proposed for the detection of wear in a clutch.

[0023] The proposed clutch includes a wear indicator that monitors the length of the clutch actuation travel and a clutch actuation travel indicator whose position depends on, or from which, the length of the clutch actuation travel can be read. Since the clutch actuation travel indicator is often inaccessible without tools, the invention proposes to detect its position using a sensor. By using a sensor, information about the position of the clutch actuation travel indicator can be obtained. Consequently, the length of the clutch actuation travel, or the position of the clutch actuation travel indicator, is correlated with the degree of clutch wear to assess the wear level.This allows maintenance measures to be taken in a timely manner to prevent clutch failure and extend the clutch's service life.

[0024] It is understood that the core of the invention relates to the wear indicator. A wear indicator can be designed as a separate module for integration into a coupling or as a component of the coupling.

[0025] Advantageous designs and further developments result from the further sub-claims as well as from the description with reference to the figures in the drawing.

[0026] According to a preferred embodiment of the invention, the sensor is designed as a Hall sensor and the position encoder as a magnet or ferromagnetic material. A Hall sensor measures the Hall voltage, which is caused by a magnetic field.

[0027] The use of a Hall sensor in combination with a magnet or ferromagnetic material as a position transmitter ensures contactless and therefore wear-free position detection.

[0028] The combination of Hall sensor and magnet or ferromagnetic material is insensitive to contamination, moisture and temperature fluctuations.

[0029] The voltage output of the Hall sensor is directly proportional to the position of the magnet and therefore to the wear. This simplifies calibration compared to other measurement methods.

[0030] Instead of a Hall sensor, other sensor types can also be used to measure wear. Potentiometers, inductive sensors, capacitive sensors, or optical sensors can detect changes in the position of a position sensor, allowing conclusions to be drawn about the wear level. The choice of sensor depends on the specific requirements and environmental conditions of the application.

[0031] According to a preferred embodiment of the invention, the wear indication includes an interface to a display device to indicate the determined degree of wear.

[0032] This ensures that the degree of wear can be easily read without the use of tools. For example, the display can be directed at the driver and prompt them to service the clutch. Accordingly, the display can be integrated into the interior, cockpit, or cab of a vehicle.

[0033] According to a preferred embodiment of the invention, the position sensor is attached to the clutch actuation travel indicator in such a way that the position sensor moves together with the clutch actuation travel indicator relative to a housing, in particular the servo housing, the amplifier housing and / or the wear indicator housing, and the sensor is not designed to be movable relative to the housing.

[0034] According to a preferred embodiment of the invention, the wear indicator is a component of a clutch comprising a force transmission means for transmitting force from an actuating means to a downstream component, which travels a clutch actuation path during actuation or has an interface to such a clutch.

[0035] In one embodiment, the power transmission means is designed as a piston disc which moves the clutch actuation travel indicator depending on the clutch actuation travel.

[0036] A piston disc in a clutch is a circular component located inside a cylinder and moved by hydraulic or pneumatic pressure to actuate the clutch. It serves to transmit the movement of the pushrod and / or piston rod and to establish the mechanical connection between different parts, for example, a pushrod and a piston rod of the clutch system.

[0037] According to a preferred embodiment of the invention, the coupling has a servo housing, an amplifier housing and a wear indicator housing, or the wear indicator has a wear indicator housing.

[0038] The division into a servo housing, an amplifier housing and a wear indicator housing enables a modular design that supports easy assembly and maintenance of the coupling components.

[0039] The specific arrangement of the housings allows for optimized electromagnetic shielding of the wear indicator unit.

[0040] The division into different housings facilitates the integration of the wear indicator into various clutch designs and allows for adaptation to different vehicle types and applications. This also makes it possible to retrofit a wear indicator into an existing clutch.

[0041] According to a preferred embodiment of the invention, the coupling is designed as a servo coupling, wherein components for opening or closing a connection between a drive and a gearbox are contained in the servo housing, and the power transmission means is arranged in the amplifier housing.

[0042] According to a preferred embodiment of the invention, the coupling is designed as a commercial vehicle coupling.

[0043] The wear indicator in commercial vehicle clutches ensures that wear is noticeable by technical means as soon as it reaches a problematic level. CONTENT OF THE DRAWINGS

[0044] The present invention will be explained in more detail below with reference to the exemplary embodiments shown in the schematic figures of the drawings. These show: Fig. 1 A schematic block diagram of an embodiment of the invention.

[0045] The accompanying drawings are intended to provide a further understanding of the embodiments of the invention. They illustrate embodiments and, in conjunction with the description, serve to explain the principles and concepts of the invention. Other embodiments and many of the advantages mentioned will become apparent with reference to the drawings. The elements of the drawings are not necessarily shown to scale.

[0046] In the figures of the drawings, identical, functionally equivalent and equally effective elements, features and components - unless otherwise stated - are each provided with the same reference symbols. DESCRIPTION OF EXAMPLES OF EXECUTION

[0047] Fig. Figure 1 shows a servo coupling 10 with an amplifier cylinder 11, the chamber of which is bounded by an amplifier housing 6. The servo coupling 10 also includes a servo cylinder 12, the chamber of which is enclosed by a servo housing 5. The servo cylinder 12 and the amplifier cylinder 11 are arranged one behind the other.

[0048] The servo coupling 10 further comprises a piston rod 14 and a push rod 13.

[0049] The pushrod 13 is connected at a first, engine-side end to a clutch fork (not shown). A second end of the pushrod 13 is connected to the front face of a piston disc 4. The piston disc 4 divides the booster cylinder 11 into a front, engine-side section and a rear section and is displaceable within the booster housing 6 along an axis when a force acts on the servo clutch 10. The movement of the piston disc 4 engages or disengages the servo clutch 10 of an engine (not shown) of the vehicle.

[0050] The piston disc 4 is connected at its rear to the piston rod 14, which runs through the rear section of the amplifier cylinder 11 and terminates in the chamber of the servo cylinder 12. Fig. 1 the push rod 13 and the piston rod 14 are aligned coaxially with the axis of the servo cylinder 12 and the axis of the amplifier cylinder 11.

[0051] The servo coupling 10 further comprises a control valve (not shown) to regulate the pressure of the front and rear sections of the booster cylinder 11 in response to the hydraulic fluid pressure in the chamber of the servo cylinder 12. The hydraulic fluid pressure in the chamber of the servo cylinder 12 is related to a force exerted on the servo coupling 10.

[0052] When a force is applied to the servo clutch 10, air flows into the rear section of the booster cylinder 11, causing the piston disk 4 and the pushrod 13 to move towards the engine. Consequently, the rear section of the booster cylinder 11 enlarges and the front section shrinks.

[0053] Wear of the servo clutch 10 leads to component erosion. In particular, this results in changes to a clutch disc (not shown), causing it to become thinner. This causes the pushrod 13 and the piston disc 4 to shift rearward, toward the servo cylinder 12. This change in the position of the piston disc 4 also leads to a change in the position of the clutch actuation travel indicator 1, which is located in Fig. 1 is designed as a push rod 13. The change in position of the clutch actuation travel indicator 1 leads to a change in the position of the position sensor 2, which is designed as a magnet 2, with respect to the Hall sensor 3. This change in position is detected by the Hall sensor 3 and is directly related to the erosion of the clutch disc.

[0054] Magnet 2 is a neodymium magnet mounted on the pushrod 13 or the clutch actuation position indicator 1 and moves with it. As magnet 2 moves, it alters the electric field of the Hall sensor 3. This change generates a measurable voltage that is directly related to the clutch wear level. This voltage change is then displayed on a screen in the vehicle, indicating the wear level as low, medium, or high.

[0055] This ensures precise monitoring of clutch wear without the need for manual inspections. Increased reliability and safety are achieved because maintenance can be scheduled in advance, before a breakdown occurs. Furthermore, vehicle downtime is reduced, and long-term maintenance costs are lowered, as early repairs are often more cost-effective than replacing heavily worn parts.

[0056] Fig. Figure 1 shows a servo coupling 10 with an amplifier cylinder 11, the chamber of which is bounded by an amplifier housing 6. The servo coupling 10 also includes a servo cylinder 12, the chamber of which is enclosed by a servo housing 5. The servo cylinder 12 is configured to be connected to a hydraulic coupling pump (not shown). The servo cylinder and the amplifier cylinder are arranged one behind the other.

[0057] The servo coupling 10 further comprises a piston rod 14 and a push rod 13.

[0058] A piston rod is a rod-shaped component integrated into a servo cylinder that transmits the force and movement of the piston to the mechanical actuating element of a clutch.

[0059] A push rod is a rod-shaped component used to transmit mechanical forces or movements between different components.

[0060] The pushrod is connected at a first, engine-side end to a clutch fork (not shown). A second end of the pushrod is connected to the front face of a piston disc 4. The piston disc 4 divides the booster cylinder into a front and a rear section and is displaceable within the booster housing 6 along an axis when a force is applied to the servo clutch. The movement of the piston disc 4 engages or disengages the servo clutch of an engine (not shown) in the automobile.

[0061] The piston disc 4 is connected at its rear to the piston rod 14, which runs through the rear section of the amplifier cylinder 11 and terminates in the chamber of the servo cylinder 12. Fig. 1 the push rod 13 and the piston rod 14 are aligned coaxially with the axis of the servo cylinder 12 and the axis of the amplifier cylinder 11.

[0062] The servo coupling 10 further includes a control valve to regulate the pressure of the front and rear sections of the booster cylinder 11 in response to the hydraulic fluid pressure in the chamber of the servo cylinder 12. The hydraulic fluid pressure in the chamber of the servo cylinder 12 is related to a force exerted on the servo coupling 10.

[0063] When a force is applied to the servo clutch 10, fluid flows into the rear section of the booster cylinder 11, causing the piston disk 4 and the pushrod 13 to move towards the motor. Consequently, the rear section of the booster cylinder 11 enlarges and the front section shrinks.

[0064] Wear of the servo clutch 10 leads to component erosion. In particular, this results in changes to a clutch disc (not shown), causing it to become thinner. This causes the pushrod 13 and the piston disc 4 to shift rearward, toward the servo cylinder 12. This change in the position of the piston disc 4 also leads to a change in the position of the clutch actuation travel indicator 1, which is located in Fig. 1 is designed as a pushrod. The change in position of the clutch actuation travel indicator 1 leads to a change in the position of the position sensor, which is designed as a magnet 2, with respect to the Hall sensor 3. This change in position is detected by the Hall sensor 3 and is directly related to the erosion of the clutch disc.

[0065] Magnet 2 is a neodymium magnet mounted on and moving with the clutch actuation position indicator 1. As magnet 2 moves, it alters the electric field of the Hall sensor 3. This change generates a measurable voltage directly related to the clutch wear level. This voltage change is then displayed on a screen in the vehicle, indicating the wear level as low, medium, or high. Reference sign 1 Clutch actuation travel indicator 2 magnets 3 Hall sensor 4 piston disc 5 servo housings 6 amplifier housings 7 Wear indicator housings 10 servo coupling 11 amplifier cylinders 12 servo cylinders 13 Push rod 14 Piston rod

Claims

[1] Wear indication for a clutch encompassing - a clutch actuation travel indicator (1) whose position depends on the length of a clutch actuation travel; - a sensor that is set up to determine the position of a position transmitter based on a measured quantity; - the position transmitter, which is in a measurable positional relationship to the sensor, in that the position transmitter and the sensor have a variable position relative to each other; - an ECU that is configured to assign a length of clutch actuation travel to a position of the position sensor and to determine a wear degree of the clutch from this. [2] Wear indication according to claim 1, wherein the sensor is designed as a Hall sensor (3) and the position transmitter is designed as a magnet (2) or ferromagnetic material. [3] Wear indication according to one of the preceding claims, comprising an interface to a human-machine interface to transmit the determined degree of wear. [4] Wear indication according to one of the preceding claims, wherein the position sensor is attached to the clutch actuation travel indicator (1) in such a way that the position sensor together with the clutch actuation travel indicator moves relative to a housing and the sensor is not designed to be movable relative to the housing. [5] Clutch with a wear indicator according to one of the preceding claims, comprising a force transmission means for transmitting force from an actuating means to a downstream component, which travels a clutch actuation path during actuation. [6] Clutch according to claim 5, wherein the force transmission means is designed as a piston disc (4) which displaces the clutch actuation travel indicator depending on the clutch actuation travel. [7] Coupling according to one of the preceding claims 5 or 6, comprising a servo housing (5), an amplifier housing (6) and a wear indicator housing (7). [8] Coupling according to claim 7, which is designed as a servo coupling, and components for opening or closing a connection between a drive and a gearbox are included in the servo housing, and the power transmission means is arranged in the amplifier housing. [9] Coupling according to one of the preceding claims, wherein the coupling is designed as a commercial vehicle coupling.

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